1. Field of the Invention
The invention relates to a handgrip for a skiing, walking or skating pole and a handstrap fastened to the same.
2. Description of the Related Art
This type of handgrip-handstrap assemblies have been manufactured and sold for several years by the Applicant, and by other manufacturers as well. One advantage is a convenient length adjustment for transmission straps, whereby the web between the thumb and the index finger is brought to the proximity of the fulcrum or turning point between the pole and the hand. Transmission of force occurs also in a manner preferably resembling traditional belt transmission, such that the force proceeds from the opisthenar side around the ball of the thumb and the underside of the palm to transmission straps present on the front side of the palm. A control strap between the back of the hand or opisthenar and the handgrip-provides a further improvement regarding a feel or response for the pole. This type of control strap is prior known e.g. from patents NO-160116 and SE-419168, which nevertheless do not disclose a length adjustment feature for transmission straps.
Patent publication EP-0357517 discloses an assembly of a handstrap and a glove, wherein the handstrap includes a wrist-enclosing cuff which is provided with a skirt extending below the side of the palm, which attaches by way of a palm-side transmission strap to a clamping element present within a space between the thumb and the index finger and whereby the assembly consisting of a handstrap and a glove can be disengaged from the handgrip, as desired. Between the clamping element and the wrist-enclosing cuff on the opisthenar side is a control strap, having a function of retaining the clamping element within the space between the thumb and the index finger even when a grip of the hand on the handgrip is totally released. Quick-release fastening requires a release action before the hand can be disengaged from the handgrip for other duties. The strap system provided with a control strap is difficult to dimension to a correct tightness for proper skiing. The clamping element present within a space between the thumb and the index finger impedes the use of a hand released from the handgrip for other duties. The clamping elements also hamper the length adjustment of a strap system to fit hands of various sizes. The wrist-enclosing cuff is located in a wrong position, on the wrong side of the wrist joint, with the result that there is no strap portion in the opisthenar area to take up a force occurring during a thrusting action.
In the above type of a handgrip-handstrap assembly, which has become known through use, the transmission straps are guided inside the top end of the handgrip through a single opening present on the rear side of the handgrip. Thus, the fulcrum of power transmission is set at a small distance from the center axis of a pole and the transmission straps apply stress on the web between the thumb and the index finger over a narrow zone.
This drawback appears also in the solution disclosed in patent EP-0357517. The latter involves a further drawback that the skier cannot freely choose his or her gloves according to the size of his/her hand and/or weather conditions but is compelled to wear the glove equipped with transmission straps and clamping elements. The range and availability of such gloves is of course less diversified and abundant than those of mere gloves.
Patent U.S. Pat. No. 4,775,168 discloses a handgrip-strap assembly, wherein the handstrap has its ends mounted with pivot axles on opposite sides of the handgrip. The handstrap has its length adjustment included in the strap section placed on the opisthenar side, which is a considerably more unreliable solution than a length adjustment implemented in connection with clamping elements and which additionally limits the possibilities of giving a handstrap an ergonomically flared design. In other respects as well, the handgrip design serves alpine skiing and is poorly suitable for cross-country skiing, e.g. for the reason that the mounting axle for handstrap ends is located too close to the top of the handgrip, the design of whose rear portion as a backward-extending dog is not fit for cross-country skiing as the pole swings to form a direct extension of the arm during a backswing action of the arm.